[eeesprit]

NB - Sorry for the english mistakes that would certainly follow...

First of all, good evening !

I'm working on a project, which aim is to study the possibility or not to cool the fuel cell of my school's car prototype, using the depression created by a Venturi which would be integrated on the structure of the vehicle.

The thermic part is over - now i wanna to see the impacts on the car's aerodynamics, especially drag coefficient Cd.

I started with very simple shapes : cylinder in an air flow - i am satisfied with the results which are very close to the theory.

Before trying to mesh complex shapes (i.e. the shape of the car) i would like to try with this :

a Venturi inluded in a Sphere (see the attached picture)

Because i'm beginner with ICEM & Fluent, i don't know how to mesh such a situation. Indeed, there are some "isolated walls" just in the middle of our an air flow.

Anyway, i tried to do something like that :

- definiting 3 surfaces for the Fluid (air)
- meshing these surfaces (i tried both TRI & HEXA unsuccessfully)
- setting boundary conditions
(by the way... what's the appropriate boundary condition for separation between my "fluid" surfaces ? interior ? interface ? thanks)

BUT

when i try to read the mesh with Fluent :

...
Warning: Invalid face type 1. Skipping
...
Warning: cell 0 of thread 46 has NULL face pointer 2.
Clearing partially read

Error: Build Grid: Aborted due to critical error.

I read some posts on this forum with users who had the same problem : it was often related to "Uncovered Faces".
But i check the mesh, and there aren't any "Uncovered Faces".

Any ideas where the problem could come from ??

Thank you very much.

Thibault